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Topic 4.1 Ionic bonding and structure

  • Positive ions (cations) form by metals losing valence electrons.
  • Negative ions (anions) form by non-metals gaining electrons.
  • The number of electrons lost or gained is determined by the electron configuration of an atom.
  • The ionic bond is due to electrostatic attraction between oppositely charged ions.
  • Under normal conditions, Ionic compounds are usually solids with lattice structures.

Course materials

Class presentation to take notes and put into notebook:
Topic 4.1 Ionic Bonding & Structure

Homework Assignments:
Intermolecular Forces (use Molecule Simulation below)
Formation of Ions

Molecule polarity simulation

Topic 4.2 covalent bonding

  • A covalent bond is formed by the electrostatic attraction between a shared pair of electrons and the positively charged nuclei.
  • Single, double, and triple covalent bonds involve one, two, and three shared pair of electrons, respectively.
  • Bond length decreases and bond strength increases as the number of shared electrons increases.
  • Bond polarity results from the difference and electronegativities of the bonded atoms.

Course materials

Class presentation to take notes and put into notebook:
Topic 4.2 Covalent Bonding

Homework:
Bonding Activity

Ionic vs covalent bonding tutorial

Topic 4.3 covalent structures

  • Lewis (electron dot) structure show all the valence electrons in a covalently bonded species.
  • The octet rule refers to the tendency of atoms to gain a valence shell with a total of eight electrons.
  • Some atoms like, Be and B, might form stable compounds with incomplete octets of electrons
  • Resonance structures occur when there's more than one possible position for a double bond in a molecule.
  • Shapes of species are determined by the repulsion of electron pairs according to the valence shell electron pair repulsion (VSEPR) theory
  • Carbon and silicon form covalent network (giant covalent) structures.

Course materials

Class presentation to take notes and put into notebook:
Topic 4.3 Covalent Structures

Homework:
Construct a Lewis Structure
Modeling Molecular Shapes

molecule polarity tutorial

drawing lewis structures tutorial: basic structures

Drawing lewis structures tutorial: resonance structures

Topic 4.4 

  • Intermolecular forces include London (dispersion) forces, dipole-dipole forces, and hydrogen bonding.
  • The relative strengths of these interactions are London(dispersion) forces < dipole-dipole forces < hydrogen bonds.

Course Materials

Class presentation to take notes and put into notebook:
Topic 4.4 Intermolecular Forces

Homework:
Intermolecular Forces Activity

Intermolecular forces tutorial

Topic 4.5 Metallic Bonding

  • A metallic bond is the electrostatic attraction between a lattice of positive ions and delocalized electrons.
  • The strength of the metallic bond depends on the charge of ions in the radius of the metal ion.
  • Alloys usually contain more than one metal and have enhanced properties.

Course materials

Class presentation to take notes and put into notebook:
Topic 4.5 Metallic Bonding

Homework:
Metallic Bonding Video

Study guides for unit exam

Application and Skills Checklist (IB Specific): Chemical Bonding & Structure Study Guide
Chemical Bonding & Structure Practice Questions: Topic 4 Practice Questions